Hi All,
I have a 1999 JDM 40th SPI Mini that is giving me some grief with more and more frequent bad running, lack of power and backfiring. I have connected my laptop with Web MemsFCR and after ECU resetting, fault clearing and clearing the adaptable values I set up idle steps and the lost motion gap and restarted the vehicle from what I believe to be a fresh start. All the sensors appeared to work correctly and while the car ran better it still had the lack of power and occasional backfiring. I did notice that the O2 sensor readings always seemed to read low. I found that the green signal wire and 12v heater wire had partially rubbed thru where they are routed behind the fuel trap bracket at the rear of the injection system. This was repaired and unfortunately the symptoms didn't appear to change. Measuring the output of the O2 sensor at the input pins of the ECU (pins 159-7 and 159-18) I get what looks to be the correct voltages going into the ECU but it still reads low on Web MemsFCR by about 350-400mv consistently.
I've ended up inside the ECU thinking there may be a dry joint on the plug or something. I found the LM9044V IC in the ECU that is the Lambda Sensor Interface Amplifier, and the voltage at the IC input pins reads the lower voltage that Web MemsFCR indicates and not the higher values that are on the ECU input pins. After some mucking around applying heat and cold to various components I found that if I played around with a small capacitor that is across the IC input pins the ECU reads the correct voltages for a short period indicating that the capacitor is a bit suspect. Unfortunately I cant see a value on it as it to small, would any of you gurus happen to of heard of this problem before and know the value of the capacitor by any chance. My gut and reading of the data sheet for the LM9044V IC makes me think a 0.01uF should work but it would be good to confirm.
Apologies for the long winded explanation. Any help would be greatly appreciated. I would send it to the gurus but as I'm in Australia it becomes a bit of a nightmare with international postage and such.
Cheers
Dean
